Oscillographic plotting system



Oct, 20, 1953 R. w. LocKHART oscILLoGRAPHIc PLOTTING SYSTEM 5Sheets-Sheet l Filed Aprill?. 1951 ANN NEEM: .Zo

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OSCILLOGRAPHIC PLOTTING SYSTEM Filed April 17, 1951 5 Sheets-Sheet 2Oct. 20, 1953 R. w. LocKHART 2,656,536

oscILLoGRAPHIc PLoTTING SYSTEM Filed April 17, 1951 5 Sheets-Sheet 5Oct. 20, 1953 R. w. LocKHART oscILLoGRAPHIc PLOTTING SYSTEM 5Sheets-Sheet 4 Filed April 17, 1951 Qwxmll Oct. 20, 1953 R. w. LocKHARToscILLoGRAPHIc PLOTTING SYSTEM 5 Sheecs-Sheet 5 Filed April 17, 1951able.

Patented 'ct 20, 1953 UNITED STATES PATENT OFFICE OSCILLOGRAPHICPLOTTING SYSTEM Robert W. Lockhart, Chicago, Ill., assignor toStewart-Warner Corporation, Chicago, Ill., a corporation of VirginiaApplication April 17, 1951, Serial N0. 221,429

14 Claims.

This invention relates to devices for providing continuous oscillographcplots of a dependent variable as a function of an independent vari- Forexample, the dependent variable may be the electrical output of a radioreceiver, and the independent variable may be the orientation of adirection finding loop which supplies radio signals to the receiver. Theinvention is also applicable to panoramic radio reception, in which casethe dependent variable is the output of a radio receiver and theindependent variable is the position of a tuning control forming a partof the receiver.

An object of the invention is to provide an improved oscillographicpolar plotting arrangement.

A further object is to provide an improved instantaneous polar plottingarrangement providing a high order of accuracy in the plotting of theindependent variable. Related to direction finding, this objectcontemplates a high order of accuracy in the plotting of the orientationof the revolving loop antenna.

A further object is to provide an oscillographic polar plottingarrangement which is particularly adapted for providing remoteindications.

A further object is to provide an oscillographic polar plotting systemwhich utilizes a high free quency current to carry information withregard to the dependent and the independent variables.

A further object is to provide an oscillographic polar plotting systemwhich incorporates means to correct for inaccuracies in the angularconiiguration of the deilecting system of a cathode ray oscillographtube forming a part of the plotting system.

A further object is to provide an oscillographic polar plottingarrangement incorporating a rotatable device for giving information withrespect to an independent variable such as orientation, together lWithmeans to correct for any slight inaccuracies in the construction of thedevice.

A further object is to provide an improved oscillographic directionfinding system or the like in Which the length of cables extending froma remote loop antenna is not critical.

A further object is to provide an improved oscillographic directionfinding system or the like in which the speed of rotation of the loopantenna may vary considerably.

Further objects, advantages, and features of the invention will becomeapparent from the following description of illustrative embodiments ofthe invention. In the course of the description reference will be madeto the drawings, in Which:

Fig. 1 is a block diagram illustrating a polar plotting arrangementconstructed in accordance with the invention;

Fig. 2 is a diagrammatic illustration of a re- 'olver which may form apart of the system of Fig. 3 is a block diagram of a direction findingvsystem constructed in accordance with the invention;

Fig. 4 is a block diagram of a panoramic radio receiver constructed inaccordance with the invention;

Fig. 5 illustrates a modified arrangement to correct for slightinaccuracies in the construction of the resolver and the oscillographtube;

Fig. 6 is a vector diagram illustrating the op eration of thearrangement of Fig. 5;

Fig. 7 illustrates a combination direction finding and panoramicreceiver constructed in accordance with the invention;

Fig. 8 is an elevational view taken as indicated by the line 8--8 inFig. 7

Fig. 9 is a, sectional view taken as indicated by the line 9*9 in Fig.7`; and

Fig. 10 illustrates a modified direction finding and panoramic receivingsystem. A The system of Fig. 1 includes a carrier oscillator I0 whichproduces a high frequency sine Wave output as indicated by anoscillogram I2. The output of the carrier oscillator I0 is transmittedby an amplitude modulator I4 to a resolver I6. The output of theamplitude modulator Id is modulated in accordance with the output of asource of information signals I8, the output of the source I8 beingapplied to the amplitude modulator. The resolver and the source ofinformation signals are connected to a motor 22 by driving means 20.

The resolver I6 provides two output signals which are fed to a pair ofcarrier reinserters 23 and 24. Signals from the carrier oscillator IIJare also applied to the carrier reinserters.

The outputs of the respective carrier reinserters 23 and 24 aredemodulated by individual demodulators 26 and 28. The outputs of thedemodulators 26 and 28 are applied by deflection ampliers 30 and 32 tohorizontal deflecting plates 3B and 31 and vertical deflecting plates 34and 35, respectively, of a cathode ray oscillograph tube 40.

One advantageous construction of the resolver I6 is shown in Fig. 2. Themodulated carrier input is applied by brushes d2 and 44 and signals. Inthis case the output of the amplitude frequency signal having amplitudeas indicated-by an. O-utput No.` 1 of therresolver |6.

modulator is a carrier a constant peak oscillogram G. l is representedby an oscillograrn fgfandoutput No. 2 is represented by an oscillogram64. The rst output produces the oscillogram S2 because the couplingbetween the rotatingpriinary coilA 5G and the stationary secondary coil,52..varies in accordance with the absolute value of the sine of. the.positional angle vof theprimary coil 50. The coupling between therotatable primary coiL andthestationary coil E'varies inaccordaxicewith.the absolute value of the cosine of the positional angle'of the coil5U: In the; posi'- tion ofthe coil 56..show n, the coupling betweenthecoil 50' andY the secondary 52' is zero, While the coupling betweenthe primary 5S and the' sec'- ondary Ellis at a maximum.

Tlevoltage in each of' the secondaries 52 and 54'" reverses in polarityeach Atime the voltage passes through a null. The oscillogram; 62": hasa null 6|',1.. The'V portion ofthe oscillogram to the l'eit 'of the nullrepresentsA a voltage having one polarity, andthe .portion to the rightAof the null represents avoltage having the opposite polarity. The`portion ofthe oscillo'gram ,6ftv between nulls 63'and 85 represents awave having one polarity, and the'`V remaining portions represent a wavehaving the opposited polarity;

The oscillograms 62and .'64" represent the equivalent of the side bandsof amplitude modulated waves .without the carriers of the waves. Thecarriers are reintroduced bythezcarrier reinserters 23 and zato produce'outputsyhaving oscillograms Band 68;. v

It should be ,noticedA in the oscillo'gram, 661 'that the carrier waveand therst'out'put of the resolver, represented by-the oscillogramjlareadditivelyphased for the first half go'f' the" oscill'ogram 6.;andsubtractively phasedfor thesecond half... The. carrier Awavelandthe'second output; representedby they oscillogram Ell; Aare' sub'-tractively I phased for the@l first and last quartersoftheoscillogram'ta, and additively phasedfo the central "half portion.VThe oscillograms and" 68` represent amplitude modulated Waves whichIaredemOdulatedby the demodulators4 26 and v28'to-produce-outputshavingVY oscillograrns l0 and 12. The outputsof Ythe'demodul'ators 26and 2,8 are sine waves which are 90-'electrical degrees-out of phasewith eac-h other;` Thephase disp'lacenfient of -theoutputs of thedemodulators results from the physicaldisplacement of the secondarywindingsfErZ-` and-54.

The outputs of the demodulators'ZSand 28 -are amplie'd by the deflectionamplifiers 3U andl 32, and are i impressed upon the horizontal plates 3Eand-3 andthe vertical plates 34 an'd'zfre-` spectively, of the -cathoderay'oscillograph tube 4U. The two voltagesdeflect-the electron beam ofthe oscillographtube to produce a circular trace or pattern 14. Theinstantaneous' position of the electron beamasit traces the pattern 'I4'corresponds -to the instantaneous angular position of `the rotatablecoilV 5f)` of the' resolver Hi;y Consequently, the position of theelectron beam is an accurate indication of the phasing or position ofthe cyclical driving means Z which drives the source of informationsignals I8.

In the course of its cyclical operation by the driving means 26, thesource of information signals i8 usually produces signals atsome denitepoints inl itsoperatiOnal cyclone These: signals produce amplitudevariations in the outputs of the amplitude modulator I4 and the resolverThe resulting variations in the outputs of thezdemodulators v25 and 28produce radial displacements vof the pattern produced by the cathode`ray oscillographitube, at points correspond- .ing .to`.the'positions ofthe source of information signals when the signals are produced. Thusthe angular position ofthe electron beam in the cathoderay tube itcorresponds to an independent variable which in this oase is the phasingor position of the driving means 2l. The radial position of the electronbeam corresponds to a dependent'variable, which inthis case is theamplia continuous polar plot of the dependent Variable asa functionofthe independent variable on the VfluorescentV screen of the `cathoderay tube 40.

The system of Fig.3 is very similar to the system ofFi`gs.-1 and 2, andvcorresponding componentsin the two systems have lbeen given the samereference characters. Y

In thearrangement of Fig) 3 the source of information signals takes theformof a radioireceiver i'having a rotatable loop antenna 82. Theloop8f2fis' driven from 'the' motor 221 by the driving means 2|).

Astne loop rotates, it produces an output having-an oscillogram 84:1'Theexact nature of the -oscillogram depends upon the directionfrom whichthe -radio signals vare received. The receiverfflproducesan outputhaving-an oscillogram 86.' The output is applied. tothe amplitudemodulator Mp1 Thesmodulato'r provides an output whichis modulated tocorrespond with the outputothe' receiver, asindic'ate'd by anoscillogram 682-" Whenwthisioutput waveis vapplied to the resolver, thelatter-produces outputs having oscillo'grams" 90 and 92; Theseoscillograms should bev comparedwith theoscillograms (i2-and6'4lof-Ii'g". 1. The valleys 94 and-@ in the oscillogram 88'produce thevalleys 98 and l'in the oscillogramsfzand S; The nulls 6'3 and 65 inthe'osc'illogram" are; broadened by the valleys Sandlt inthe'Aoscillogram-'to produce broad nulls |68 and in the oscillogram 925"Sharp peaksi |`|2,'|f",i"and ||6 in the' envelope of the oscillograrn88"'produce corresponding peaks. |18; ELl'and |22 inthe envelope ofthe'oseillogram Th'ecarrierreinserters 23fand Ztadd carrier components ito the outputs of Y the resolver: and thereby produce outputs havingoscillograms. |24 andf.|26-. When they are demodulated by thedemoldulators 2''andA 28;"these waves produce oscillograms'f|'28"'and|30; Thexvalleys` 94 and 9.6 in the: envelope of the oscillogram` 88produce valleys:|.32.and.|34 in the .oscillogram |28@ The peaksf.. |2;I|I4, and y| I6 in the: envelope ofz'the oscillogram wproduce peaks|3'S,.'|38,"and |40 in the oscillogram--Hlfv When the wavesrepresentedby the oscillog-rams |28:` and |30'are impressed upon'thehorizontaland vertical'deecting plates respectively of the cathode rayoscillographA tube: 4B; 'the'electron beamV of the tube traces a pattern|42. The pattern |42 has a pair of diametrically opposite outwardlypointing peaks |44 and |46. The peak |44 is produced by Athe peaks |36and |40 in the oscillogram |38,

and the peak |46 is produced by the peak |38. The pattern |42 has radialnulls |48 and |50 which are produced by the valleys |32 and |34 in theoscillogram |28.

The sharp peaks ||2, ||4 and H6 in the output oscillogram 88 of themodulator I4 correspond with nulls |52, |54 and |56 in the signal fromthe loop antenna 82. Thus the radial peaks |44 and |46 in the pattern|42 traced by the electron beam in the cathode ray tube 46 correspond tothe nulls in the signal from the loop antenna. The angular position ofthe peaks |44 and |46 is indicative of the direction from which radiosignals are being received. The tube 40 may be provided with anazimuthal scale as indicated in fragmentary fashion at |41.

The embodiment of Fig. 4 is quite similar to the embodiment of Figs. land 3, and corresponding components have been given the same referencecharacters in the two figures.

In the system of Fig. 4, the source of information signals takes theform of a radio receiver |60 having rotatable tuning means |62 which isoperated by the driving means 26. rThe output of the radio receiver |60is applied to the ampli4 tude modulator |4. The motor 22 tunes thereceiver |60 from one end of its tuning range to the other. After aquick return the tuning operation is repeated. Stations, received as thefrequency band of the receiver is traversed, produce output signals inthe form of pulses |64, |66 and |68 as indicated in the oscillogram |16.As indicated in an oscillogram |12, the pulses are manifested in theoutput of the amplitude modulator in the form of valleys |14, |16 and|18, in the envelope of the output oscillogram |12.

Oscillograms |80 and |82 represent the two output signals from theresolver |6. The envelope of the oscillogram |80 has valleys |63 and |84which correspond with the pulses |64 and |68. The pulse |66 produces abroadened null |86 in the envelope of the oscillogram |86. The envelopeof the oscillogram |82 has valleys |68, |90 and |92 which are producedby the pulses |64, |66 and |68.

After the carrier is reinserted by the reinserters 23 and 24, outputsignals having oscillograms |94 and |96 are produced. The envelope ofthe oscillogram |64 has a valley |96 which corresponds with the pulse|64, and a peak 266 which corresponds with the pulse |68. 'I'he envelopeof the oscillogram |96 has a peak 262 which corresponds with the pulse|64, a valley 204 which corresponds with the pulse |66, and a valley 206which corresponds with the pulse |56.

The output signals of the demodulators 26 and 28 have oscillograms 208and 2|0. The pulses |64, |66 and |68 appear in the oscillogram 208 as avalley 2|2, a broadened null 2|4, and a valley 2|6, respectively. 'I'hepulses appear in the oscillogram 2 |0 in the form of valleys 2|8 and220, and a valley 222.

When the signals represented by the oscillograms 208 and 2|0 are appliedto the deflecting plates of the cathode ray oscillograph 40 by thedeflection amplifiers 30 and 32, a pattern 224 is traced by the electronbeam of the cathode ray tube. The pattern 224 has inwardly directedradial spikes 226, 228 and 230, which correspond with the pulses |64,|66 and |68. The an.

gular position of the spikes is indicative of the frequency of thesignals which produce the pulses in the output of the radio receiver.The uorescent screen of the cathode ray tube |40 may be'provided with acircular frequency scale, as indicated in fragmentary fashion at 232.The length of the spikes in the pattern 224 indicates the relativestrength of the stations which are being received.

In all of the embodiments of Figs. 1 through 4, the angular position ofthe electron beam .40 in the cathode ray oscillograph tube 40corresponds closely with the position of the driving means 20, providedthat the resolver I6 and the cathode ray tube 40 are accuratelyconstructed. The defiection amplifiers 30 and 32 preferably should bedirect current amplifiers in order to obtain accurate indications of theposition of the driving means 20 when the latter is stationary, ormoving at extremely low speeds.

In practice, errors are likely to exist in the perpendicularity of thesecondary windings 52 and 54 in the resolver I6, and in theperpendicularity of the vertical deflecting plates 34 and 35 and thehorizontal deecting plates 36 and 31. Fig. 5 illustrates a modifiedarrangement to compensate for any errors which may exist. In Fig. 5 thedeflection amplifier 30 is shown as having output conductors 240 and242, and the deflection amplifier 32 has output conductors 244 and 246.A voltage dividing resistor 248 is connected across the outputconductors 240 and 242, and a voltage dividing resistor 250 is connectedacross the output conductors 244 and 246. The voltage dividing resistorshave respective fixed taps 252 and 254 which are connected together by aconductor 256.

The horizontal deflecting plate 31 is connected to a slider 258 whichcontacts the voltage divider or potentiometer 248 adjacent its end whichis connected to the conductor 240. The other horizontal deflecting plate36 is connected to a slider 260 which contacts the voltage divider 250adjacent the tap 254.

The vertical deiiecting plate 34 is connected to a slider 262 whichcontacts the voltage divider 250 adjacent its end which is connected tothe output conductor 244. The other vertical defleeting plate 35 isconnected to a slider 264 which contacts the voltage divider 248adjacent the tap 252.

The taps 260 and 264 may be adjusted to cornpensate for any error inperpendicularity of the resolver secondary coils 52 and 54 or thedeflecting plates of the oscillograph tube 40. Adjusting the sliders 260and 264 affects the relative phasing of the voltages applied to thevertical and horizontal deflecting plates. By means of the arrangementof Fig. 5, a portion of the horizontal deecting voltage from theamplifier 30 may be applied to the vertical deflecting plates along withthe vertical deiiecting voltage, and a portion of the vertical deectingvoltage from the amplifier 32 may be applied to the horizontaldeiiecting plates along with the horizontal deflecting voltage. Thesliders 258 and 262 provide for adjustment of amplitude of thehorizontal and vertical deflecting voltages, respectively.

The vector diagram of Fig. 6 illustrates the operation of the phasingnetwork of Fig. 5. A vector 266 represents the voltage from the slider258 to the tap 252. A vector 268 represents the voltage from the slider262 to the tap 254. Because of an error in the perpendicularity of theresolver coils 52 and 54, these voltage vectors are 'frequencycorresponding to the position of the pointer 334. Consequently thereceiver 300 is tuned to the station which produced the radial spike312.

The motor 22 rotates the loop antenna 304 to produce a direction findingpattern on the oscillograph similar to the pattern I42 in Fig. 3. Thusboth the frequency and the direction of a station are readily and`quickly ascertainable.

When the switch 354 is in its direction finding position, the tuningmeans 302 may be shifted by moving the pointer 334. The rotation of thepointer rotates the cam follower 348 and thereby produces correspondingrotation of the cardioidal cam 332. Thus when the switch 354 is set forpanoramic receiving, the frequencies of a number of stations may berecorded. The direction of each of the stations may be determined byshifting the switch 354 to its direction nding position and moving thepointer 334 successively to the positions corresponding to therespective frequencies of the stations.

The system of Fig. is somewhat similar to the system of Figs. '7 to 9,and corresponding components have been given the same referencecharacters in the various figures. The arrangement ci the pointer 334,the ring gear 333. the bearing 338, the handle 340, the gear 342, andthe shaft 344 is the same as in Fig. '7. The positioning clutch 349connects the shaft 344 with the tuning means 302 of the receiver 300.

A common shaft 380 connects the tuning means 302 with a resolver |00.'and a normally disengaged magnetic clutch 382. The tuning means 302 andthe resolver IEa may be driven through the clutch 382 by means of amotor 384.

A common shaft 300 connects the loop 304 with a resolver IED and a motor302.

A switch 394 is provided, including a movable member 396 and a pair ofxed contacts 308 and 400, The contact 398 is connected to one of theterminals of the positioning clutch 348, the magnetic clutch 302 and themotor 384. The other contact 400 is connected to one terminal of theloop motor 392. The movable switch member 380 is connected to oneterminal of an electrical power source 402. The other terminals of theclutch 34S, the clutch 382, the motor 302, and the power source 402 areconnected together by' respective ground connections, for example.

The output of the radio receiver 300 is impressed upon the amplitudemodulator I4. A changeover switch 404 is provided to connect either ofthe resolvers IEa or Ib betweenv the amplitude modulator I4 and thecarrier reinserters 23 and 24. As indicated, the switches 404 and 394may be ganged together. The switches 404 and 394 have intermediatepositions in which the resolver I5a is connected into the system, but inwhich neither of the motors 384 and 332 is energized.

The arrangement of the carrier source I0, the carrier reinserters 23 and24, the demodulators 26 and 28, the deflection amplifiers 30 and 32, andthe oscillograph tube 40 may be the same as in the system of Figs. l and3.

In the operation of the system of Fig. 10, the switches 390 and 404 mayfirst be set in their panoramic receiving positions in which theresolver I0a is connected in the circuit and the motor 384 and theclutches 343 and 382 are energized. The motor 384 drives the resolverIBa and the tuning means 302 through the clutch 382, but the pointer 334remains stationary because the positioning clutch 340 is disengaged. Theloop 304 remains stationary since the motor 392 is not energized. Theresolver |01) is disconnected during panoramic receiving.

During panoramic receiving, the arrangement of Fig. 10 operates in muchthe same manner as the panoramic receiver of Fig. 4. As indicated inconnection with Figs. '7 to 9, a pattern having radial spikes isproduced by the oscillograph 40. The pointer 334 is rotated by means ofthe handle 340 until the pointer is lined up with one of the spikes.

The switches 394 and 404 may then be shifted into their directionfinding positions in order to engage the positioning clutch 343,disengage the magnetic clutch 382, stop the motor 384, and energize themotor 392. As described in connection with Figs. '7 to 9, thepositioning clutch 349 rotates the tuning means 302 until the receiver300 is tuned to the frequency corresponding to the position of thepointer 334. This operation tunes in the station which produces thespike with which the pointer 334 was aligned.

The motor 392 drives the resolver ISD and the loop antenna 304. It maybe advantageous to rotate the loop 304 at a higher speed than the speedof rotation of the tuning means 302. During direction finding, thearrangement of Fig. 10 operates in much the same manner as the directionfinding receiver of Fig. 3.

By means of the system of Fig. 10, both the frequency and the directionof an intercepted station may be determined readily. The loop antenna304, the resolver |61) and the motor 392 may be located at a greatdistance from the remainder of the components of the system. No extendedmechanical linkage is required. The lengths of the cables connecting theloop 304 with the receiver 300, and the resolver I9b With the changeoverswitch 404, are not critical since no complicated phasing problems areinvolved. Moreover, any phasing errors may be corrected by means of anarrangement such as that shown in Figs. 5 and 6. The speeds of themotors 384 and 392 are not critical since the output voltages providedby the resolvers I 3a and I 6b do not vary with the speed of theresolvers. As previously indicated, the resolvers Ilia and I6?) givepositional indications even when they are stationary.

The arrangement including the pointer 334 and the handle 340 provides amanual tuning dial for the system of Fig. 10. When the switches 394 and404 are in their intermediate positions, the system is adjusted formanual tuning. The motors 334 and 392 are rdisconnected and the magneticclutch 332 is disengaged. However, the positioning clutch 346 is engagedso that the tuning means may be adjusted by shifting the position of thepointer 334. During manual tuning, the resolver Ita is connected in thesystem so that the electron beam of the cathode ray oscillograph 40 isdisplaced radially when a station is tuned in manually.

During direction nding, the tuning means may also be adjusted manuallyby shifting the position of the pointer 334. Thus, the frequencies ofseveral stations may be recorded during panoramic receiving, and thenthe system may be tuned manually during direction finding to determinethe direction of each of the stations.

aesesso In the direction finding system of Fig. Sithe loop 3.2, themotor 2?., andthe resolver Iiimay be located a great distance.from'therother components of the system. '.Alternativelyythe carriersource lo', the modulator "IIL-fthe icarrierreinserters 23 and24,'and'the demodulators'zb` and 28may also belocated remotely fromtheother components, alongfvvith the 'loop,`the motorand the resolver.The lengthsof the .cables interconnecting the various Vcomponents' arenot' critical. The speed ofl'the motor 22 may'vary'wid'ely withoutaffecting the accuracy vofthe. `directional indications or the size 'ofthe pattern.` produced by the oscillographv 40.

Many of the details of rthe embodiments described above are merelyillustrative and should not be takenas limitative. The inventionV may bepracticed in manyv equivalent forms. VvThe scope of the invention isindicated by the followingv claims:

I claim:

1. An apparatus to provi'de'contirruous pol-ar plots of a dependentvariable as a function of an independent variable, "comprising drivingmeans for cyclical-ly* `varying 'the 'independent variable, meanstoproduce electrical information signals corresponding tovariation-softhe dependent variable, avsource of a" carrierV wave, a modulator tocombine: the' carrier wave vand the information signals'to provide ahigh frequency output wave modulated in accordance with the informationsignals, a resolver including rst and second relatively rotatable means,one ofthe means being rotatively connected with the driving means andthe otherhaving a stationary mounting, a primary coil on thei rst meansconnected to the output of the modulator, first and secondsecondarycoils carried at right angles on the second means, the prima-ry fandthe` secondaries being inductively'coupledy firstk andl second carrierreinserters to mix carrier; components from they carrier sourceI Withtheoutputs-"of 4the rst and second 'secondaries-tof produce outputs whichare amplitude modulated inquadrature in accordance with the cyclicalvariation-ofthe .in- .l

dependent variable, first and seconde demodulators receiving theoutputsfof thecarrier-rein'- serters andproviding-f'demodula-tedoutputs,-and an oscillograph having horizontaldele'ctin-g meansV connected to the output of the.- first 'demodulatorand vertical deflectingf means `connected to the outputy ofthesecondedemodulator.

"2. Anoscillographic( directionvapparatus, comprising aradio:receiverhaving afro.- tatable loop antenna, driving means for* rotatingthe antenna, a sourcect a carrier Wave; aernodu- Y lator to combine thecarrierwaveand the voutput of the receiver to provide a high frequencywave modulated in accordance withv thereceiverY output a `resolverincluding first -andsecond relativelyv rotatablel means, oneof the meansbeing rota-tively connected with the driving means and the'other: havinga sta-tionarymountng, a primary coil: on the firstfmeans'connected totheoutput of the -inodulatoig first and second 4secondary coils carried .atrighty angles on thezsecondmeans, the .primary andtheseconda-ries-.being inductively coupled, rst and second carrierreinserters to Vmix carrier components from the carrier: source Withlthe outputs of the rst and second lsecundarios to 'produce outputs which.are amplitude. modulated in quadrature' inV accordance. with therotational position of the. loop, first and second demodulatorsAreceiving. the: outputs or the -carrier reinserters and providinglde--l2 modulated outputs, and an oscill'ographhaving horizontal deiiectingmeans ccnnectedfto the out vput of the iirst demodulator and verticalded'ecti-ng' means'con-nected to the output of the second demodulator.3.' An -oscillographcy panoramic radio receiving system, Vcomprising aradioreceiver `'havin-g cyclficallyI variable tuning means, drivingmeans for varying the tuning means, a source :ofV a. carrier wave,- -amodulatortov combine .the Ycar-- rer- Wave and the output .ofthenrcceivermto provide al high frequency voutput Wave modulated in`raccordance 'with the 'receiver output, aeresolver including rstwand-:second relatively vrotatable means, ori-eroi the meansfbeing'rotatively connected with the driving means and'thefother having astationary mountin-g,. a primarycoil on thev rirst` r means connectedtothe voutput of the modulator, -i'irst and'lsecond secondarycoilscarried at right angles on the secondmeans,=the primaryy andthesecondariesA beingY inductivcly coupled, i first vand second carrierreinserters to mixcarrier components from thecarrier source With theoutputs of the rst-.fand second-seeondariesT to produce outputs which.are amplitude modulated in quadrature -in accordance with thecyclicallvariation-of the tuningA means, -rst and second demodulatorsreceiving the outputs Aof the carri-erv reinsertcrs and `providing.demodula-ted outputs; and anloscillograph having horizontal defiectingmeans-connectedtothe output of the iirst demodfulatorl andverticaldeflectngY means connected to the outputof the second`demodulater.

4. In an appara-tus to provide .instantaneous oscillographic indications.of rotational-position, first and second relatively rotatable means, aprimary coil carried. by the rst means. a` source of a carrier Wave.having yits'output.,connler-.tted- -to the prim-ary coil, i'irstand-*second` 'secondary coils coupled to` the primary'col and carried bythe second means approximately .atrightangles-to each other,` first .andsecond carrier .reinserters having inputs connected tothe first andsecond secondary coils andother inputs connected to the carrier'- sourcetoy lprovide respective outputs which .are amplitude modulated inquadrature in accordance vvith-` relative; rotationotthe rst and. secondrotatable means,anoscillograph haw ing horizontal andVvertical-denecting means, and rst-land second demodulators supplied.from the outputs of the respective iirst and` second .carrerreinsertersV toy supply .signals in quadrature tothe horizontal and:vertical detlectingr means l for producing.indications-.ontheoscillograph in accordancefvvi-th relative rotation oi the. rst andsecond rotatable means..

. Y5. In anapparatus to-produce a circular oscillographc.r pattern-,first -and second -sources .providing rst and second signalsapproximately quadrature, fan oscillograph having horizontall and.vertical deiecting' means, means supplying ama-jor portion of the'rstsignal :to the horizontal ideiiecting;l 'means-l means supplying amajorportion .of theqsecond signal' to the-vereticalfdeiiectingrmeans,means supplying a minor portion of the rst signal to the verticald'eecting' means', and-meanssupplyng al'minor: .portion of the secondsignal` to the horizontal deiiectingi means.

- 6; Inv :an 0apparatus for.` vproducing a circular oscillographictrace, iirst and-.second sources pro-v viding iirstV and ksecondsigna-lsf:approXir-natelyf in quadrature',. anoscillograp'h having firstand' second deiecting means-one of the deiiecting'meansV beinghorizontal and the other being vertical deecting means, means supplyingthe first signal to the first defiecting means, means supplying thesecond signal to the second deflecting means, and means additionallysupplying a portion of the first signal to the second deiiecting meansto compensate for any errors in the perpendicularity of the deectingmeans and in the phase perpendicularity of the signals.

7. In an apparatus to provide instantaneous oscillographic indicationsof rotational position, rotatable generating means to provide iirst andsecond output signals approximately in quadrature in synchronizationwith rotation of the generating means, an oscillograph having first andsecond deflecting means, one of the deflecting means producingapproximately horizontal deflection and the other producingapproximately vertical deiiection, means to supply the first signal tothe first deiiecting means, means to supply the second. signal to thesecond deflecting means, and means additionally to supply a portion ofthe first signal to the second deflecting means, to compensate for anyerror in the perpendicularity of the deflecting means or in the phaseperpendicularity of the signals.

8. An apparatus to provide continuous oscillographic polar plots of adependent variable as a function of an independent variable, comprisingdriving means for cyclically varying the independent variable, means toproduce electrical information signals corresponding to variations ofthe dependent variable, a source of a carrier wave, a modulator tocombine the carrier Wave and the information signals to provide a highfrequency output wave modulated in accordance with the informationsignals, a resolver including first and second relatively rotatablemeans, one of the means being rotatively connected with the drivingmeans and the other having a stationary mounting, a primary coil on thefirst means connected to the output of the modulator, first and secondsecondary coils coupled to the primary coil and carried approximately atright angles on the second means, first and second carrier reinsertersto mix carriery components from the carrier source with the outputs ofthe iirst and second secondaries to produce outputs which are amplitudemodulated approximately in quadrature in accordance with the cyclicalvariation of the independent variable, rst and second demodulatorsreceiving the outputs of the carrier reinserters and providingdemodulated outputs, an oscillograph having first and second deflectingmeans, one of the deflecting means providing approximately horizontaldefiection and the other providing approximately vertical deflection,means supplying the output of the rst demodulator to the first deiectingmeans, means supplying the output of the second demodulator to thesecond deflecting means, and means additionally supplying a portion ofthe output of the first demodulator to the second deflecting means tocompensate for any error in the perpendicularity of the secondary coilsor in the perpendicularity of the deflecting means.

9. A receiving system for providing oscillographic indications of thefrequency and direction of a station, comprising a radio receiver havingrotatable tuning means and a rotatable loop antenna, respective means torotate the tuning means and the loop antenna, a source of a carrierwave, a modulator to amplitude modulate the carrier wave in 'accordancewith the output of the receiver, means including a rotary resolver toutilize the output of the modulator for providing first and secondsignals amplitude modulated in quadrature to correspond with rotation ofthe resolver, means to rotate the resolver in accordance with rotationof one of the loop antennas or the tuning means, first and seconddemodulators to demodulate the first and second signals, an oscillographhaving horizontal deiiecting means connected to the output of the firstdemodulator and vertical deecting means connected to the output of thesecond modulator, a pointer adjacent the oscillograph movable intoalignment with an oscillographic indication of the frequency of astation when the tuning means is being rotated, and means forming apositioning connection between the pointer and the tuning meansoperative to position the tuning means at the frequency setting to whichthe pointer is adjusted when the loop antenna is being rotated.

10. A receiving system for providing oscillographic indications of thefrequency and direction of a station, comprising a radio receiver havingrotatable tuning means and a rotatable loop antenna, a motor, first andsecond clutches forming disengageable driving connections from the motorto the tuning means and the loop antenna respectively, operating means`to engage the clutches alternatively, a source of a carrier Wave, amodulator to combine the carrier wave and the output of the receiver toprovide a high frequency output Wave modulated in accordance with theoutput of the receiver, a resolver including first and second relativelyrotatable means, one of the means being driven by the motor and theother having a stationary mounting, a primary coil on the iirst meansconnected to the output of the modulator, first and second secondarycoils coupled to the primary coil and carried at right angles to eachother on the second means, rst and second carrier reinserters to mixcarrier components from the carrier source with the outputs of the firstand second secondary coils to produce outputs which are amplitudemodulated in quadrature in accordance with rotation of the motor, firstand second demodulators receiving the outputs of the carrier reinsertersand providing demodulated outputs, an oscillograph having horizontaldeflecting means connected to the output of the first demodulator andvertical deilecting means connected to the output of the seconddemodulator, a pointer adjacent the oscillograph movable into alignmentwith an oscillographic indication of the frequency of a station when thetuning means is being driven through the rst clutch, and means forming apositioning connection between the pointer and the tuning meansoperative to position the tuning means at the frequency setting to whichthe pointer is adjusted when the loop antenna is being driven throughthe second clutch.

11. A receiving system for providing oscillographic indications of thefrequency and direction of a station, comprising a radio receiver havingrotatable tuning means and a rotatable loop antenna, respective means torotate the tuning means and the loop antenna, a source of a carrierwave, a modulator to amplitude modulate the carrier wave in accordancewith the output of the receiver, means including a rotary resolver toutilize the output of the modulator for providing first and secondsignals amplitude modulated in quadrature to correspond with rotation ottneresolizer; selectively .operable means;l tofrotate theresolverinasynchronizationY withA the tuningA means 'orizthe' loopantenna, rst yand lsecondidemodul'ators Vto:demoduiate' the first andsecondi signals;y and :an osci-llograph having horizontaldeflectingmeans connected to theloutput oithe. first d'emodulator and verticalAdeiiecting means:.connectedl tol output or. thelsecond demodulator;

l 125A; receiving system fori providing oscillographic indicationsV yci'v.the 'trequency andf` directionf ot a station; comprising a radioreceiver. having'rotatablertuningfmeans. and a' rotatable-loop antenna,Arespectivenrean's. .to rotate the tuning meansa and' the loopiantenna, asource of a carrienwave, afrmoduiatcr to combine the carrier Wavelandthe outputot'the receiver Vtoprovide alhighfirequency output Wavemodulated in aeeoit'clance with' the output: `of theY receiver,. avresolver includingrst and second relatively rrotatable means, means toproduce relative rotation of ftlretrst, a1-id.l second means in'accordance with rotationof one of tne'tuningmneans orthe loop antenna; a'primary'coi'l" orrthe.- rst means connectedi tothe` output of; themodulator, iirst and secon'difrsecondary coilscoupled" to the primarycoil and carriedfat'right angles. to each 'other omthefseccnd means, andsecond carrier reinserters` to fmix carrier components from the carrier'sourceI` Witlrther'outputs of the first `and secondsecondaries toproduce outputs which are amplitude-'modulated in quadrature inaccordancewithirelativerotaton ofthe` irst and second meanaaiirstan'dasecond demodulatorsreceving the' -outpuilsfnrv thercarrierfreinserters and providingcd'emodula'tedioutputs; and anoscillographihaving. horizontal deiecting: means connected'to the:output .of therst' idemodulator and) Iverticaldeiiectingrnleans'connected to the output `ci? vthe second demodulatoiu 123.432' receivingsystem for -proviclingtv oscilloe graphic-'indications offith'eirequencyfan'd direction-of. afstation,'comprising'afradio receiver,having rotatable tuning? means 'and a rotatable loop antenna,respective; motors to zdrive the tuning me'a'nswand the-loopantenna,`operating means to Venergize the: motors alternatively', a source. ofaca-rrier Wave, aI modulator to an'lpiititdeV modulatert'lue:y carrierwave-in `accordance, with' the output of' .the receiver;means"including`a pair .of

resolvers ldriven 'byr'the 'tuning meansV and'` the loopv antennarespectively Yto utilize the output of. the modulator for .providingfirs-tranci second' signals amplitudexmodulated .in euadratlnfe tocorrespondl with: rotation rof thetuning means orxthelcop antenna, nrstandsecond'demoduvlatorsztn demodulateithegiirst, and second signals,-

switching. means: alternatively toV connect eachI` of' the resolversfor'operation, andi an oscillograpn having horizontal deiecting meansconnect'ed'4 to rtheoutput `of the first demodulator andverticaldeflecting means connected totheoutputv ofthe second demodulator.

14. A receiving systemi for; providing oscillographic' indications; ofythe frequency anddirection; of a station; comprising a radioreceiverhaving rotatable tuning meanswand;v a rotatable means respectively, aprimary'coilfon'eaclrof the rst means, first and second secondary coilscoupled to the primary coil and carried at' right angles to veach* otheron each-ofthe second means,` nrst and second carrier reinserterstomixxcarrier components from the carrier, source WithA the outputs of thenrst and .secondf sccondaries Vonone of the resolvers to produceoutputsv Whichf are amplitude modulated in-quadratureiinaccordance withrotation of the antenna or thetuningmeans, means alternatively toconnect eachofthefresolversrbetween themodulator and the carrierreinserters, rst and second demodulators-receiving the outputs of thecarrier reinserters and providing demodulated outputs, and anoscillograph having horizontal deiiecting means connected to the outputof the rst demodulatorand vertical delecting means connected totheoutput of the second demodulator.

ROBERT LOCKH-ART.

References Cited inthe file-of this patent UNITED STATESV PATENTS NumberName Date 1,994,232 Schuck' Mar.,1'21935' 2,403,967 Busignies July 16,1946 2,475,212 Wolfi July 5, 1949 2,476,977 Hansel VJuly-26, 19492,477,557 Torsch July 26T, 1949 2,574,946 White Nov; V13, 1951

